If you thought social media was taking over the world, then the following Glassdoor list of the best tech companies to work for should only confirm this impression: The top three slots are taken by some of the most well-known social networking sites on the planet. Of course, there are plenty of other tech niches represented in Glassdoor's annual "Employees' Choice: Best Places to Work" awards, including software development, unified communications, business process automation and—in the case of Google—enough IT-related pursuits to make your head spin. As always, we've included samples of Glassdoor's employee reviews of the included companies. (Certain comments were lightly edited in the interest of clarity.) While these reviews have a lot to say about plentiful food and drinks, fitness classes, scooters, onsite health care and cube-decorating competitions, we're focusing less on perks and more on the career development side of the respective corporate cultures. The rankings were compiled based on more than half a million company reviews from employees.